My B3200 HST is no longer starting. It worked for a quick trip across the field, then refused to re-start. Prior to the field trip, it had been VERY low on fuel, but I did refill before starting the first time, and (as I said) it ran fine for a short trip.

The lights work, but I only intermittently hear the solenoid engage, and the engine won't turn at all. I've tried jiggling the PTO lever and the gear lever. I checked the solenoid fuse - fine. I messed with the seat sensors too, to no avail. The battery indicator is green.

One more clue from further experimentation... if I'm not sitting on the seat, but I turn the key to the first position (not all the way to start position, just the first), sometimes I hear the solenoid engage, but other times I hear a sort-of buzzing or vibrating sound from behind the dashboard.

Is this normal? Could the solenoid be bad? Or, is it still a safety switch I'm looking for?

One more clue from further experimentation... if I'm not sitting on the seat, but I turn the key to the first position (not all the way to start position, just the first), sometimes I hear the solenoid engage, but other times I hear a sort-of buzzing or vibrating sound from behind the dashboard.

Is this normal? Could the solenoid be bad? Or, is it still a safety switch I'm looking for?

Again, I appreciate your help. I know little about fixing tractors.

Eric

That sounds bad. Not aware of any solenoids behind the dash. Maybe a bad relay. Do you hear the fuel solenoid on the engine click when you turn the key?

Yes, the headlights go out when I try to start. Someone suggested to me that the problem is with grounding.

When I initially turn the tractor key into the first position (not all the way to start), the headlights won't shine at all. It takes several minutes (despite warm weather) before they finally come on. Meanwhile, I hear a faint humming or buzzing sound from behind the ignition switch area. The solenoid does not seem to engage (click) consistently, but gets better once the "warm up" of several minutes completes. Also, the fuel gauge rises very very slowly (several minutes) after turning the key to the first position.

Once the lights are on, turning to start causes them to go out completely.

The tractor is not that old - 2 years. It has about 80 hours. Just had it in for general maintenance this Spring.

How do I chase down a problem with the electrical ground (or whatever this is)? I checked the battery connection and chassis connection (looks fine).

Sounds like to me that you have either a very bad battery connection or a poor battery. Have you tried to jump it from a car with battery cables?
Pull the battery out and have it load checked at most auto parts stores. I believe the battery is the same as a lot of Honda automobiles use.